Presently, a battery management system is commonly provided for very complex electrical and electronic-based circuits or devices, such as laptop computers, which typically utilize rechargeable batteries. In these applications, the battery management system typically provides a specialized serial interface, such as the SMBus, for interfacing with an external controller such as a micro-controller. These battery management systems consist of specialized circuitry which is optimized for the unique chemistry of the specific battery type being monitored and controlled, i.e. nickel cadmium, lithium, etc. The battery management system and the associated microcontroller incorporate current or voltage level monitoring techniques to switch between battery sources and/or to shut down the device being powered at a battery discharge level that is controlled by data stored in memory. These battery management systems are of a greater complexity and cost than can be justified for less expensive devices.